First of all I woukd like to say that your framework is one of the ones I like the most when developing mine...
I know it's a big file but it is because it has a lot of comments, I have to work on the sass version to change the comments style...the minified version is close to 133 kb or so...but I definitely have to reduce it and make it lighter...
Hey Kurenn, I would pay close attention to every CSS rule and really think about if it's needed or not. Also, try to follow some CSS principle such as OOCSS or SMACSS so that you reduce selector bloat.
ie: ".tabbar-inner { ... }" is better than ".tabbar .inner { ... }"